﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Configuration;
using System.Collections;
using System.Data.SqlClient;
using System.Data;

/// <summary>
/// The SqlHelper class is intended to encapsulate high performance, 
/// scalable best practices for common uses of SqlClient.
/// </summary>
public abstract class SQLHelper
{

    //Database connection strings
    //public static readonly string CONN_STRING = ConfigurationSettings.AppSettings["SQLConnString1"];
    public static readonly string StrConn = ConfigurationManager.ConnectionStrings["StrConn"].ConnectionString;
    public static int BASE_COUNT = 0;
    // Hashtable to store cached parameters
    private static Hashtable parmCache = Hashtable.Synchronized(new Hashtable());

    /// <summary>
    /// Execute a SqlCommand (that returns no resultset) against the database specified in the connection string 
    /// using the provided parameters.
    /// </summary>
    /// <remarks>
    /// e.g.:  
    ///  int result = ExecuteNonQuery(connString, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24));
    /// </remarks>
    /// <param name="connectionString">a valid connection string for a SqlConnection</param>
    /// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
    /// <param name="commandText">the stored procedure name or T-SQL command</param>
    /// <param name="commandParameters">an array of SqlParamters used to execute the command</param>
    /// <returns>an int representing the number of rows affected by the command</returns>
    public static int ExecuteNonQuery(string connString, CommandType cmdType, string cmdText, params SqlParameter[] cmdParms)
    {

        SqlCommand cmd = new SqlCommand();

        using (SqlConnection conn = new SqlConnection(connString))
        {
            PrepareCommand(cmd, conn, null, cmdType, cmdText, cmdParms);
            int val = cmd.ExecuteNonQuery();
            cmd.Parameters.Clear();
            return val;
        }
    }

    /// <summary>
    /// Execute a SqlCommand (that returns no resultset) against an existing database connection 
    /// using the provided parameters.
    /// </summary>
    /// <remarks>
    /// e.g.:  
    ///  int result = ExecuteNonQuery(connString, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24));
    /// </remarks>
    /// <param name="conn">an existing database connection</param>
    /// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
    /// <param name="commandText">the stored procedure name or T-SQL command</param>
    /// <param name="commandParameters">an array of SqlParamters used to execute the command</param>
    /// <returns>an int representing the number of rows affected by the command</returns>
    public static int ExecuteNonQuery(SqlConnection conn, CommandType cmdType, string cmdText, params SqlParameter[] cmdParms)
    {

        SqlCommand cmd = new SqlCommand();

        PrepareCommand(cmd, conn, null, cmdType, cmdText, cmdParms);
        int val = cmd.ExecuteNonQuery();
        cmd.Parameters.Clear();
        return val;
    }

    /// <summary>
    /// Execute a SqlCommand (that returns no resultset) using an existing SQL Transaction 
    /// using the provided parameters.
    /// </summary>
    /// <remarks>
    /// e.g.:  
    ///  int result = ExecuteNonQuery(connString, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24));
    /// </remarks>
    /// <param name="trans">an existing sql transaction</param>
    /// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
    /// <param name="commandText">the stored procedure name or T-SQL command</param>
    /// <param name="commandParameters">an array of SqlParamters used to execute the command</param>
    /// <returns>an int representing the number of rows affected by the command</returns>
    public static int ExecuteNonQuery(SqlTransaction trans, CommandType cmdType, string cmdText, params SqlParameter[] cmdParms)
    {
        SqlCommand cmd = new SqlCommand();
        PrepareCommand(cmd, trans.Connection, trans, cmdType, cmdText, cmdParms);
        int val = cmd.ExecuteNonQuery();
        cmd.Parameters.Clear();
        return val;
    }

    /// <summary>
    /// Execute a SqlCommand that returns a resultset against the database specified in the connection string 
    /// using the provided parameters.
    /// </summary>
    /// <remarks>
    /// e.g.:  
    ///  SqlDataReader r = ExecuteReader(connString, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24));
    /// </remarks>
    /// <param name="connectionString">a valid connection string for a SqlConnection</param>
    /// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
    /// <param name="commandText">the stored procedure name or T-SQL command</param>
    /// <param name="commandParameters">an array of SqlParamters used to execute the command</param>
    /// <returns>A SqlDataReader containing the results</returns>
    public static SqlDataReader ExecuteReader(string connString, CommandType cmdType, string cmdText, params SqlParameter[] cmdParms)
    {
        SqlCommand cmd = new SqlCommand();
        SqlConnection conn = new SqlConnection(connString);

        // we use a try/catch here because if the method throws an exception we want to 
        // close the connection throw code, because no datareader will exist, hence the 
        // commandBehaviour.CloseConnection will not work
        try
        {
            PrepareCommand(cmd, conn, null, cmdType, cmdText, cmdParms);
            SqlDataReader rdr = cmd.ExecuteReader(CommandBehavior.CloseConnection);
            cmd.Parameters.Clear();
            return rdr;
        }
        catch
        {
            conn.Close();
            throw;
        }
    }
    /// <summary>
    /// 
    /// </summary>
    /// <param name="connString"></param>
    /// <param name="cmdType"></param>
    /// <param name="cmdText"></param>
    /// <param name="cmdParms"></param>
    /// <returns></returns>
    public static DataSet ExecuteSet(string connString, CommandType cmdType, string cmdText, params SqlParameter[] cmdParms)
    {
        SqlCommand cmd = new SqlCommand();
        SqlConnection conn = new SqlConnection(connString);
        try
        {
            PrepareCommand(cmd, conn, null, cmdType, cmdText, cmdParms);
            SqlDataAdapter dad = new SqlDataAdapter();
            dad.SelectCommand = cmd;
            DataSet ds = new DataSet();
            dad.Fill(ds);
            conn.Close();
            return ds;
        }
        catch
        {
            conn.Close();
            throw;
        }
    }
    /// <summary>
    /// Execute a SqlCommand that returns the first column of the first record against the database specified in the connection string 
    /// using the provided parameters.
    /// </summary>
    /// <remarks>
    /// e.g.:  
    ///  Object obj = ExecuteScalar(connString, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24));
    /// </remarks>
    /// <param name="connectionString">a valid connection string for a SqlConnection</param>
    /// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
    /// <param name="commandText">the stored procedure name or T-SQL command</param>
    /// <param name="commandParameters">an array of SqlParamters used to execute the command</param>
    /// <returns>An object that should be converted to the expected type using Convert.To{Type}</returns>
    public static object ExecuteScalar(string connString, CommandType cmdType, string cmdText, params SqlParameter[] cmdParms)
    {
        SqlCommand cmd = new SqlCommand();

        using (SqlConnection conn = new SqlConnection(connString))
        {
            PrepareCommand(cmd, conn, null, cmdType, cmdText, cmdParms);
            object val = cmd.ExecuteScalar();
            cmd.Parameters.Clear();
            return val;
        }
    }

    /// <summary>
    /// Execute a SqlCommand that returns the first column of the first record against an existing database connection 
    /// using the provided parameters.
    /// </summary>
    /// <remarks>
    /// e.g.:  
    ///  Object obj = ExecuteScalar(connString, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24));
    /// </remarks>
    /// <param name="conn">an existing database connection</param>
    /// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
    /// <param name="commandText">the stored procedure name or T-SQL command</param>
    /// <param name="commandParameters">an array of SqlParamters used to execute the command</param>
    /// <returns>An object that should be converted to the expected type using Convert.To{Type}</returns>
    public static object ExecuteScalar(SqlConnection conn, CommandType cmdType, string cmdText, params SqlParameter[] cmdParms)
    {

        SqlCommand cmd = new SqlCommand();

        PrepareCommand(cmd, conn, null, cmdType, cmdText, cmdParms);
        object val = cmd.ExecuteScalar();
        cmd.Parameters.Clear();
        return val;
    }

    /// <summary>
    /// add parameter array to the cache
    /// </summary>
    /// <param name="cacheKey">Key to the parameter cache</param>
    /// <param name="cmdParms">an array of SqlParamters to be cached</param>
    public static void CacheParameters(string cacheKey, params SqlParameter[] cmdParms)
    {
        parmCache[cacheKey] = cmdParms;
    }

    /// <summary>
    /// Retrieve cached parameters
    /// </summary>
    /// <param name="cacheKey">key used to lookup parameters</param>
    /// <returns>Cached SqlParamters array</returns>
    public static SqlParameter[] GetCachedParameters(string cacheKey)
    {
        SqlParameter[] cachedParms = (SqlParameter[])parmCache[cacheKey];

        if (cachedParms == null)
            return null;

        SqlParameter[] clonedParms = new SqlParameter[cachedParms.Length];

        for (int i = 0, j = cachedParms.Length; i < j; i++)
            clonedParms[i] = (SqlParameter)((ICloneable)cachedParms[i]).Clone();

        return clonedParms;
    }

    /// <summary>
    /// Prepare a command for execution
    /// </summary>
    /// <param name="cmd">SqlCommand object</param>
    /// <param name="conn">SqlConnection object</param>
    /// <param name="trans">SqlTransaction object</param>
    /// <param name="cmdType">Cmd type e.g. stored procedure or text</param>
    /// <param name="cmdText">Command text, e.g. Select * from Products</param>
    /// <param name="cmdParms">SqlParameters to use in the command</param>
    private static void PrepareCommand(SqlCommand cmd, SqlConnection conn, SqlTransaction trans, CommandType cmdType, string cmdText, SqlParameter[] cmdParms)
    {
        BASE_COUNT++;
        if (conn.State != ConnectionState.Open)
        {
            conn.Open();
        }

        cmd.Connection = conn;
        cmd.CommandText = cmdText;

        if (trans != null)
            cmd.Transaction = trans;

        cmd.CommandType = cmdType;

        if (cmdParms != null)
        {
            foreach (SqlParameter parm in cmdParms)
                cmd.Parameters.Add(parm);
        }
    }

    /// <summary>
    /// 检查in是否含有非法字符或者是字母
    /// </summary>
    /// <param name="str"></param>
    public static void CheckInValue(ref string str)
    {
        if (str.Trim().Length != 0)
        {
            string[] arr = str.Split(',');
            for (int i = 0; i < arr.Length; i++)
            {
                try
                {
                    Int32.Parse(arr[i].Trim());
                }
                catch
                {
                    arr[i] = "0";
                }
            }
            str = string.Join(",", arr);
        }
        else
        {
            str = "0";
        }

    }
    /// <summary>
    /// 返回Int值
    /// </summary>
    /// <param name="obj"></param>
    /// <returns></returns>
    public static int IntParse(object obj)
    {
        int i = 0;
        Int32.TryParse(Convert.ToString(obj), out i);
        return i;
    }
}
